Reverberatory sound-horn.



W. A. CHAPMAN.

REVER-BEHAT'ORY SOUND HORN.

APPLIGATlON FILED JULY 10, 1908.

957,654, Patented May 10,1910.

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UNITED STATES PATENT OFFICE.

WILLIAM ALBERT CHAPMAN, 0F SMITI-IVILLE, ARKANSAS.

REVERBERA'IOBY SOUND-HORN.

To all whom it may concern:

Be it known that I, WVILLIAM ALBERT CHAPMAN, a citizen of the United States, and a resident of Smithville, in the county of Lawrence and State of Arkansas, have in-' vented a new and Improved Reverberatory Sound-Horn, of which the following is a full, clear, and exact description.

In the use of the ordinary trumpet-shaped metallic horn for the production of sounds, either of speech or musical notes, I have ob served that in addition to the existence of the fixed ratio between the size of the horn and the sound volume, there is also an attendant tone pitch that is inherent in and pe culiar to horns of such form and material. This tone pitch is quite pronounced, and varies with the shape and size of the horn and in horns of like size and shape, such as are composed of several pieces, which, in the joining, are often forced together, placing each piece under tension or strain varying both in direction and in intensity in the several members. This condition attaches to and colors every tone of the reproduction, imparting to each musical. tone a false shading, often rendering it shrill, tremulous and metallic, and, again, harsh, grating and rattling, changing the notes of the piano to discordant cries and those of a violin to flute-like tones; characteristic peculiarities of the individuals speech are lost and strange effects introduced. Such discords are in part due to the kind and state of the material employed, and in part to the shape of the completed horn, which, if in trumpet form, enforces a constriction or concent. tion of tones and a blast or megaphone-like delivery, carrying with it the false sound waves of irregular depth and measure that are developed by the secondary vibrations of the unequally disposed parts of the horn. If the horn be small, shrillness, lack of body and expression in the tones of reproduction are its characteristics, while if the horn be large the tones are more pleasing by reason of being of greater depth and more sonorous, covering so to speak the defects observant in the small horn. Many disadvantages incident to the use of the large horn are such as its bulky form, insecure fastening and the room it occupies, which, together with its long leverage on the support, is a prolific source of accident. In my investigations I have found that the modificationof the form of the horn may not Specification of Letters Patent.

Application filed J u1y 10, 1908.

- sounds.

Patented May 10, 1910.

Serial No. 442,857.

only be made effective in the reduction of size and length, but also to preclude the generation of false vibratory notes, and at the same time effect the delivery of voice tones natural to the speaker and musical tones of full volume and true value in tone coloring and expression. I have further found that certain materials lend themselves to the reproduction of sounds more perfectly than others, the vibrative sound thereof being in itself harmonious, full and low in effect, reinforcing the reproduced musical Of such materials I have found that certain specially prepared woods, glass, porcelain, papier-mach, well lacquered and formed under heavy pressure are among the best; silver, aluminum, brass and copper spun into form and specially prepared are a so well adapted to the purpose.

In the manufacture of this invention I prefer the bell or resonator made of opalescent glass or porcelain, and the reflector, of like material but of solid color, the ma terial being superior and affording opportunity to secure the novel and beautiful effects that are varied and highly ornamental by means of reflected light. In the practical production of this invention the materials that may be used successfully, differ in degree and tone of resonance and may be further varied in character by slight change in form and arrangement of parts, as it is evident that such modifications are inherent in the act of manufacture and may be made to embody the essential character istics of my improvement as defined in the claims hereinafter annexed.

The invention enables the manufacture of sound amplifiers as used in connection with talking machines, to be effected at a reduced cost; provides a new and novel means of increasing the artistic attractions of the room through the action of light, a reduction in the size of the horn heretofore required for the attainment of the given volume of sound, the control of the volume and tone of the sound commensurate with the size of the room in which it is placed, the elimination of all harsh and discordant notes, which are rendered true, full, resonant and in a natural manner; )revent the mingling of reproduced sounds with those of the source of which is external, and affords a self-contained and perfectly balanced amplifying horn for sound reproducing machines.

their free passage.

Having thus in general terms described the defects existing in sound amplifying devices as now used, to the removal of which and the attainment of superior results, this invention is designed, I will now by reference to the drawings, wherein like numerals designate like parts, describe the invention.

Figure 1 is a fragmentary view of a sound reproducing machine having my improved reverberatory sound horn applied thereto in its preferred embodiment; Fig. 2 is a central vertical section through the horn; and Fig. 3 is a face view of the same.

The preferable construction of my improved horn involves the use of a resonator 5, in the form of a hemispherical body slightly deeper than half its diameter and constructed of glass, porcelain, wood or other suitable resonant material, of uniform density and thickness, provided with a circular central opening 6 in its inner end or bottom for the passage of sound waves, and, further, where such body is of glass or porcelain, with a flange for connecting it to a sound tube 7. This sound tube 7 is in the nature of a metallic arm of gradually increasing size, and curved to conform with the curvature of the resonator 5 and effect ing its placement well back of the machine, as illustrated in Fig. 1. The tube 1 serves the dual purpose of a support for the reso nator, and a sound tube, and since it is securely and firmly united thereto it is in effect the same as one piece. The lower end of the tube 7 is designed to fit snugly into the socket provided for horns in the horn support of the machine, and is limited in its passage thereinto by a bead 8, arranged externally of the tube a suitable distance above its extremity. At the junction of the tube is a bell-shaped resonator; the former curves inwardly in the form of a hemisphere having its center at or near the center of the opening (3, and serves for the deflection of the sound waves directly through this opening against the face of a reflector 9 arranged in the resonator 5, and movably opposed to On the rear face of the hemispherical end of the tube is secured, by making as an integral part or otherwise afiixing, a boss 10, the bore of which is in exact alinement with the center of the resonator 5, in which is slidable a rod or stem 11 adapted to be secured in adjusted position by suitable means, such as a set-screw 12 threaded through the boss 10. The inner end of the rod 11 extends within the resonator where it supports the sound reflecting device 9, through which the adjustment of the latter is effected, the stem 11 being provided with a knob 13 at its rear end for this purpose. By reason of the particular mounting of the stem 11 and the association of the reflector therewith, the latter is supported centrally within the resonator and out of contact with any part thereof. By this construction the relative position of the tube reflector, the movable reflector or reverberatory lens and the resonator changes the angles at which the sound waves impinge,

for the alteration of the sound volume as otl erw se pgg ifying'the tone. "The form adopted for the reflector is, as clearly shown in Fig. 2, an outer hemisphere having an inner hemisphere superposed on its bottom or rear face, the two being constructed of one piece and of a weight suflicient to prevent as far as possible all vibration. l/Vithin the smaller hemisphere is placed a small electric bulb 1 1, which is backed by foil attached to that part of the larger hemisphere and covering that por tion of the smaller one. The conductors to the light, which ordinarily connect with a small battery, pass through the rear or bottom side of the smaller sphere at suitable points. lVhile light forms a valuable addition to my improvement, it is nevertheless in no wise essential as regards etliciency in sound reproduction, and may be dispensed with if desired, the sole purpose being simply to obtain the attractive play of the changeable and irridescent light reflected from the vibrating-surfaces of the resonator. Resonance is a desirable feature in the resonator 5, and is provided for in the se lection of the material, the thickness and evenness of the walls, the form and depth of the resonator and its prevention of con tact at any point other than that at the joint made with the tube.

In the reflector or reverberatory lens, neither resonance nor vibration is desired, its province being the deflection of sound waves issuing from the mouth of the tube against the walls of the resonator, there to be thrown forward in parallel lines. As these sound waves issue through the sound tube 7, they pass in parallel lines against the reflecting face of the reflector and by it are spread over the back interior face of the resonator, which in turn delivers them outwardly in parallel lines.

Having thus described my invention, I claim as new and desire to secure by Letter Patent:

1. The combination of a resonator having a sound-conveying tube leading thereto, and a hollow sound reflector supported within and spaced from the resonator, with the discharge ends of the tube and resonator facing in the same direction and the tube discharging into the space between the resonator and reflector.

2. The combination of a resonator having a sound-conveying tube leading thereto, and a sound reflector supported in the resonator and movable forwardly and rearwardly therein to and from the tube forward of the discharge end thereof.

3. The combination of an approximately hemispherical resonator having an opening in the bottom, and a sound tube intermediate its length, conforming to the curvature of the resonator'and having a substantially hemispherical extremity attached to the resonator over said opening.

4. The combination of a horn for sound reproducing machines, of opalescent material, and a combined sound and light reflector of like material arranged within the horn.

The combination of a resonator, a sound tube leading to and attached to the resonator, and a reflector within the resonator,

adju'stably supported on the tube, with the tube dischar ing externally of the resonator.

6. The combination of a resonator, and a reflector consisting of two hemispheres imposed one on the other, arranged in the resonator, with the enlarged ends of the hemispheres facing outwardly.

7. The combination of a resonator, and a reflector within the resonator comprising a hemisphere having a smaller hemisphere imposed thereon, witlrthe resonator and hemispheres facing in the same direction.

8. The combination of a resonator, a sound-conveying tube leading to and connected with the resonator, a stem slidable through the rear wall of the tube in substantial axial alinement with the resonator, and a reflector carried on the stem.

9. The combination of a resonator, a tube leading to and connected with the resonator and provided with a boss, a stem slidabl-e through the boss and tube in axial alinement with the resonator, a reflector carried on the stem, and a set-screw threaded through the boss adapted to bind on the stem and secure the reflector in adjusted position.

10. The combination of a resonator, a sound-conveying tube leading to the resonator, and a reflector supported within and isolated from the Walls of the resonator, having the rear external face thereof opposed to the discharge end of the tube.

11. The combination of a hemispherical resonator provided with an opening, and a sound tube having an approximately hemispherical portion connecting the resonator over said opening.

12. The combination of a resonator comprising two approximately hemispherical.

the sound waves after the latter have first passed from the tube into the resonator.

141-. The combination of a resonator consisting of a hemispherical body imposed upon by a body of like form, and a reflector of a form corresponding to the shape of the resonator and arranged therein.

15. The combination of a soundtransmission tube, a reflector arranged at the front of the discharge end of the tube to externally intercept the sound waves, and a resonator surrounding the reflector and isolated therefrom, forming an annular passage for the escape of the sound waves from the tube.

16. The combination of a resonator through which light is adapted to pass, a reflector arranged within the resonator consisting of two hemispherical bodies of different size, and a light arranged within the smaller body.

17. The combination of an approximately hemispherical resonator having an opening in the curved wall thereof, and a sound tube leading to the resonator, having an approximately hemispherical discharge end relatively smaller than the resonator and communicating therewith through said opening.

18. The combination of a resonator constructed of a material penetrablc by light, a reflector within the resonator, having a light, and means to move the reflector relatively to the resonator to produce variable light and tone effect-s.

19. The combination of a resonator of a material penetrable by the light, a combined sound and light reflector supported within the resonator, and a light supported adjacent to the reflector.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

VILLIAM ALBERT CHAPMAN.

lVitnesses H. C. STEADMAN, D. H. KAISER. 

